Device for making sound effects



Aug 19, l947- L. J. WITTE ErAL 2,425,975

DEVICE FOR MAKING SOUND EFFECTS Filed April 5, 1944 2 Sheets-Sheet 1 Am/M/a/v i E la '[4 a 2 2 4 P I E', 1 I: l Ei 2 C I 57 62 O T`cal Go l' 59 l: I E' El Jmzvz'ozzs Louis I Witte BY Z .en/'mm H. .Southland W ATTORNEY Aug. 19, 1947. 1... wma Em n 2,425,975 DEVICE FOR MAKING SOUNDy EFFECTS Fned `April 5; 1944 2 sheets-sheet 2" Lows J.' Witte .Beit/'amm Hmzlnnd Wm] Arrows Patented Aug. 19,1947

DEVCE FR MAKING SOUND EFFECTS Louis John Witte, Beverly Hills, and Benjamin Harrison Southland, West Los Angeles, Calif., assignors to Twentieth Century-Fox Film Corporation, Los Angeles, Calif., a corporation of New York Application April 5, 1944, Serial No. 529,686

-'9 Claims.

1 This invention relates to the art of sound effects and deals particularly with a device adapted to produce a sound eect which can be used to imitate machine guns, airplanes,

. motors, or any other device wherein an intermittent, sharp staccato noise is required.

The invention to be hereinafter described has been developed in connection with the motion picture industry, but it will become obvious to those skilled in the art that the device may bc used in other industries, such as radio programs, theatres, etc., wherein sound eiects of the above nature may be needed.

The principal object of the invention is to provide a piece of apparatus that will produce a repeating, sharp, staccato report simulating a machine gun. Another and an important object is to provide a device of the above character which combines with the report a coordinated ash which gives a realistic visual as well as an auditory imitation of an actual report from the barrel of a gun. Still another object is to provide a device of the character described wherein the combustible gas and the compressed air which are mixed to produce a combustible mixture are utilized to propel a small engine which by its own motion meters the gas and the air in the proper proportions to provide a highly combustible mixture. A further object is to provide a piece of apparatus as described wherein the same engine which measuresrthe gas is utilized to operate a make and break ignition system similar to an automobile system for producing an intermittent firing of the mixture. A still further object is to provide a small piece of apparatus for the purpose described which may be built into the space provided by the jacket on a standard machine gun. In this way the whole device may be incorporated in the machine gun without changing the outward appearance. Other objects and advantages will become apparent asthe description proceeds in conjunction with the drawings in which:

Figure 1 is a plan view partly in section of our device;

Figure 2 is a sectional view partly in section taken on line 2-2 of Figure l;

Figure 3 is a schematic diagram showing the electrical circuit used in conjunction with our invention;

Figure 4 is a schematic arrangement of the valves used in controlling the gases supplied to our invention;

Figure 5 is an inverted rear end view of our invention;

' Figure 6 is a view taken on line 5-6 of Figure 5'l yFigure '7 is a sectional view taken on line I-l of Figure 2; and y Figure 8 is a view taken on line B-B of Figure l. Briefly stated, our invention amounts to yutilizing the well known arrangement of a piston and cylinder for measuring gas which is to be mixed for explosive purposes. In our invention we employ one or more cylinders having reciprocable pistons therein and arrange the cylinder or cylinders in a well known manner whereby they become an engine and rotate a crank shaft having a fly wheel thereon. All of this construction is well known in the art. However, we utilize the arrangement to produce a new and unusual result.

In the drawing, and particularly in Figures 1 andl 5, it can be seen that our invention comprises two cylinders II and I2 and that these cylinders aremounted on the side of a block generally designated I3. Also mounted in the block I3 is a shaft I4 having on its outer ends disks I5 and I6 which serve as fly wheels and also as means of connecting a crank arm to the shaft I4.

It is to be'understood in the ensuing description that although we have shown two cylinders Il and I2 we will nevertheless describe but one cylinder, since the construction of the two cylinders is identical and the description of one will serve for both. In this case we will describe cylinder II.

Referring more particularly to Figure 1, it will be noted that cylinder `II has a piston I'I reciprocably mounted therein. piston Il is a connecting rod Ill which passes out of one end of the cylinder through a packing gland I9. The outer end of the rod I8 is pivotally connected to the disk I5 at an eccentric point by a pin 20. Under this arrangement it is evident that the reciprocation of the piston I'I will rotate the wheel I5.

As before stated, the cylinders II and I2 are pivotally mounted on the side of the block I3. The structure for this purpose consists in making the cylinders with a fiat face 2| which slidably Connected to the4 vbear against the side 22 of the block 3 26 in the block I3. It will also be noted that the end ofthe member 23 is provided with a point 21 to provide easy rotation of the cylinder on the pivot 24. It will be observed that the cylinder I I is provided with ports 28 and 29 on opposite ends of the cylinder. These ports are for the purpose of admittinggas into the cylinder on opposite sides of the piston I1. Under the arrangement shown here, we propose to admit air into the cylinder through the port 28 and gas through the port l29. For this purpose the block I3 is provided with a series of ports and passages which will now be described.

Referring shown partly in section, it will be noted that the block is provided with passages 30, 3|, 32, and 33, together with passages 34, 35, 36, and 31, which communicate in the following manner: The passage 34 communicates with the passage 30; the passage 35 communicates withV the passage 32; the passage 36 communicates with the passage 3|; and the passage 3Ivcommunicates with the passage 33. As shown in this view, the passage 34 is connected to a compressed air supply, not shown, by means of a ypipe 38, while the passage 35 is connected vto a gas supply, not shown, by means of a pipe 39. These two connections may be reversed if desired, the only requirements being in this case that air is supplied to one end of the cylinder and gas to the other. On the other side of the block, the passage 36 is provided with a fitting 40 and the passage 31 is provided with a similar iitting 4|. 'Ihe purpose of these two ttings is `to mount -a member generally designated 42, which is provided with a passage 43 that communicates with the passage 36 through the fitting 46. The iitting 4| in the passage 31 communicates with an annular chamber 44 in the member 42, ywhich in turn connects with a mixing and ilring chamber 45. The aforementioned passage 43 ylikewise enters the same chamber, wherein the air which passes through the passage is Amixed with the gas which passes through the chamber '44. The chamber 45 is provided with a spark plug 46 for igniting and exploding the gas therein. As .the gas ignites, it explodes with a detonating eii'ect andthe iiame is discharged ithrough the opening 41,'which in vpractice would -bey placed near the `muzzle of the gun so that the name wouldtare into the open, similar to an actual gun discharge.

To explain the operationof the engine, it is necessary to refer to Figures 1, 2,'5, and 6. In the previous paragraphsit was stated that the cylinders II and *I2 were pivotallymounted -on the side of the .blockrI3 and were held in sliding engagement therewith by the spring member 23. It was also stated that Vthe face of the cylinder I I was provided with ports 28 and 29. Now then,` since the socket 25 on the cylinder II is mounted over the pivot .pin l24, the ports v26 yand 29 will I3. During rotation of the disk wheels I and I6, the cylinders will assume various angular positions on the face of the block. "The two extreme positions will be at the time the cylinders are intaking and are exhausting. Whenthe crank `arm is in the dotted .position shown in Figure v2, one of the cylinders will assume the'dotted position shown in the same figure. In this position the port 29 will communicate with the port 32, thereby admitting gas into the cylinder behind the piston I'I. The pressure of the gas will naturally force the piston to travel in the cylinder until it reaches the cylinder, whereupon the the opposite end of to Figure 2, wherein the block I3 is.

4 conductor 62 to a brush 63 held `on the block I3.

'to provide 4 port 29 then communicates with the port 33 and the port 26 at this point communicates with the port 30. This admits compressed air to the side of the cylinder opposite the gas, thus forcing the piston in the opposite direction and at the same time forcing the gas in the opposite side of the cylinder out through the port 33, where it travels through the passage 31 into the annular chamber 44 and eventually into the combustion chamcontinued movement of the piston,

where it passes into passage 43 and into the cornbustion chamber 45, where it is mixed with the gas therein. The cycle is repeated.

As shown in the drawings, we have illustrated two cylinders with their attendant working parts. However, it is obvious to anyone skilled in this art that one cylinder is a complete unit and may be used for the purpose described. There is an advantage in using two cylinders which becomes practical and useful, in that there is a better mixture of air and gas; also, if the two cylinders are not spaced diametrically apart on the crank shaft, the engine will have better starting characteristics.

In Figure 4 we have shown a valve arrangement for controlling the amount of air and gas fed to the cylinders. As shown, it comprises valves 43 and 49 in pipe lines 50 and 5I respectively, which supply the air and gas to the machine `as shown. 'I'he two lines 50 and 5I come together in a valve 52 which, as indicated, is a duplex valve for controlling both lines simultaneously.' As seen in this drawing, the valve 52 comprises a-plug having passages 53 and 54 which are arranged to simultaneously pass the air and gas out of the lines 50 and 5I and may be turned to control the iiow therethrough. In practic,e,fthe valves 48 and 49 are set to supply the proper amounts of gas and air. The valve 52 will then become the valve which controls theamount of each that is admitted to the engine. The purpose of the valves 48 and49 is to provide a highly explosive mixture inthe proper proportions and the purpose of the valve 52 is to control the speed of l,the engine and thereby the amount of explosives admitted to the explosion chamber, as well as the frequency of the explosion.

In connection with the foregoing, we provide an ignitionsystem forv intermittently electrically energizing the spark plug 46. The plug 46 functions in the well known manner. In Figures 1, 3, and 8, we have shown a system for intermittently causing an electrical discharge across the points of the plug 46. Referring to Figure 3, it will be seen that this circuit consists of a transformer generally designated `56 having primary windings 51 and secondary windings 58. In the primary circuit we incorporate a battery 59v having a switch 60 conveniently located therein. One side of the primary windings is connected by in a. bracket 64 The other side is grounded as 'I'he brush 63 in turn engages the is formedl with insulation members spaced on the periphery thereof so as contact points Gland 68 which the brush may contact on rotation of the disk to intermittently complete the primary circuit through the equipment to a ground 69. One end of the secondary circuit goes to a ground "I0, while the other end 'II goes to the spark plug 4'6. Under this arrangement it becomes evident that as soon shown at 6I. disk I6 which 65 and 66 ateatro as the engine starts operating, the wheel It starts rotating and the contact points 61 and 68 will intermittently come under the brush 63. This will interruptedly complete the circuit through the primary side of the transformer 56 which will supply a high voltage to the spark plug 46, therethe entire apparatus including the two cylinders l and the block i3 is placed in the jacket of the machine gun. The only other connections necessary are the pipes 50 and 5l which go 'to the sources of air and gas, which have not been shown.

A machine of the foregoing character will give a realistic imitation of a machine gun in actual operation. However, we are aware that with simple modifications, or even as the machine is disclosed herein, it will operate to produce other sound effects, such as airplanes, motor boats, etc. For this reason we do not wish to conne the invention to the single application shown and described, but intend it to cover all equivalent uses and applications of the inventive idea.

We claim: f

1. A device of the character described comprising a cylinder having a piston reciprocably mounted therein, means for supplying a compressed combustible gas to said cylinder at one side of said piston, means for supplying compressed air to the opposite side of said piston to reciprocate the same, a chamber for collecting and mixing the exhaust from both sides of said piston, and means for intermittently igniting the mixture in said chamber.

2. A device of the character described comprising an engine driven by a piston reciprocating in a cylinder, means for supplying compressed air and compressed combustible gas to opposite sides respectively of said piston to reciprocate the same, means for collecting and mixing the exhausts from both sides of said piston, and means for intermittently igniting the said collected mixture.

3. A device of the character described comprising an engine having a y wheel driven by a piston reciprocably mounted in a cylinder, means for supplying compressed air to said cylinder,

means for supplying a compressed combustible gas to said cylinder to reciprocate said piston therein and rotate said y wheel, a chamber communicating with said cylinder for collecting and mixing exhausted gases resulting from the operation of said engine, means for igniting the mixture in said chamber, and means associated with said ily wheel for intermittently energizing said igniting means.

4. A device of the character described comprlsing an explosion chamber having an opening to permit a ash to the atmosphere, means for supplying explosive gas to said chamber, said means including a cylinder having a piston reciprocably mounted therein with means for supplying compressed air to one side of said piston and compressed combustible gas to the other side of said piston together with means for exhausting said gases into said explosion chamber, means communicating with said explosion chamber for igniting said gases, said means including a spark plug, and means for energizing said spark plugin timed relation to the recprocaticn of said piston.

5. A device of the character described ccmprising an explosion chamber having an opening to permit a flash to the atmosphere, means for supplying explosive gas to said chamber, said means including a cylinder havingr a piston reciprocably mounted therein with means for supplying compressed air to one side of said piston and compressed combustible gas to the other side of said piston together with means for exhausting said gases into said explosion chamber, and means communicating with said explosion chamber for intermittently igniting said gases.

6. A device of the character described cornprising an explosion chamber having an opening to the atmosphere to permit a, fla-sh therethrough, means for supplying combustible gas to said chamber, said means including a cylinder having a piston reciprocably mounted therein with means for supplying compressed air to one side of said piston and compressed combustible gas to the other side of said piston together with means for exhausting said gases into said explosion chamber, and electrical means communieating with said explosion chamber for intermittently igniting said gases.

7,. A device of the character described comprising an explosion chamber, means for supplying an explosive mixture of gas to said chamber, said means including a reciprocating engine having a, .cylinder with a reciprocable piston therein adapted to exhaust gases into said explosion chamber, means for` supplying compressed combustible gas and compressed air to said engine to actuate the same and exhaust gas into said chamber, and means for intermittently igniting they gas in said chamber.

8. A device of the character described comprising an explosion chamber, means for supplying an explosive mixture of gas to said chamber, said means including a reciprocating engine having a cylinder with a reciprocable piston therein adapted to exhaust gases into said explosion chamber, means for supplying compressed combustible gas and compressed air to said engine to actuate the same and exhaust gas into said chamber, and means for exploding the gas in said chamber in timed relation to the reciprocation of said engine.

9. A device of the character described comprising an explosion chamber, means for supplying an explosive mixture of gas to said chamber, said means including an engine having a pair of cylinders each with a reciprocating piston therein, means for exhausting each end of each of said cylinders into said explosion chamber, means for supplying compressed air to one side of said piston, means for supplying combustible gas to the opposite side of each of said pistons to form an explosive mixture with said compressedl air when exhausted into said explosion chamber, and means for intermittently igniting the mixture in said explosion chamber.

LOUIS JOHN WITTE. BENJAMIN HARRISON SOUTHLAN'D.

REFERENQES iDli'iElill The following references are of record ih die ci this patent:

UTUTED STATES PATENTS Number 'Name Date 1,320,233 .l'amerson Got. 28, 3.919 1,343,456 Jones June 15, 1920 1,357,513 Pettys Nov. 2, 192@ 1,359,295 Trumbull Nov. i6, i920 

